<!DOCTYPE html>
<title>
  In effect animations should effectively apply will-change (i.e. force a
  stacking context) (ref)
</title>
<link rel="help" href="https://drafts.csswg.org/web-animations-1/#side-effects-section">
<link rel="author" href="mailto:bokan@chromium.org">
<style>
  .testcase {
    position: relative;
    margin: 2px;
    border: 1px solid black;
    width: 250px;
    height: 25px;
  }
  .label {
    flex-grow: 1;
  }
  .container {
    background-color: lightgrey;
    margin: 4px;
    display: flex;
    width: 600px;
    flex-direction: row;
    justify-content: flex-end;
    align-items: center;
  }
  .pass {
    width: 100%;
    height: 100%;
    background-color: limegreen;
  }
</style>

<!-- OPACITY -->

<!-- Is current - before phase playing forwards -->
<div class="container">
  <div class="label">Opacity - before phase</div>
  <div class="testcase" id="opacity-before">
    <div class="pass"></div>
  </div>
</div>

<!-- Is current - in play-->
<div class="container">
  <div class="label">Opacity - active phase</div>
  <div class="testcase" id="opacity-active">
    <div class="pass"></div>
  </div>
</div>

<!-- Is current - after phase playing backwards-->
<div class="container">
  <div class="label">Opacity - after phase</div>
  <div class="testcase" id="opacity-after">
    <div class="pass"></div>
  </div>
</div>

<!-- TRANSFORM -->

<!-- Is current - before phase playing forwards -->
<div class="container">
  <div class="label">Transform - before phase</div>
  <div class="testcase" id="transform-before">
    <div class="pass"></div>
  </div>
</div>

<!-- Is current - in play-->
<div class="container">
  <div class="label">Transform - active phase</div>
  <div class="testcase" id="transform-active">
    <div class="pass"></div>
  </div>
</div>

<!-- Is current - after phase playing backwards-->
<div class="container">
  <div class="label">Transform - after phase</div>
  <div class="testcase" id="transform-after">
    <div class="pass"></div>
  </div>
</div>

<!-- BACKGROUND COLOR -->
<div class="container">
  <div class="label">Background-color - before phase</div>
  <div class="testcase" id="bgcolor-before">
    <div class="pass"></div>
  </div>
</div>

<!-- Is current - in play-->
<div class="container">
  <div class="label">Background-color - active phase</div>
  <div class="testcase" id="bgcolor-active">
    <div class="pass"></div>
  </div>
</div>

<!-- Is current - after phase playing backwards-->
<div class="container">
  <div class="label">Background-color - after phase</div>
  <div class="testcase" id="bgcolor-after">
    <div class="pass"></div>
  </div>
</div>
